With the continuous development of display technology, augmented reality (AR) technology has wide application prospect in the fields such as game, medical treatment, shopping and military affairs due to superior human-computer interaction experience. Therefore, more and more manufacturers are committed to research and development of transparent display products and realize the AR technology through transparent screens.
Electrochromic (EC) materials refer to materials of which the optical properties (e.g., light transmittance) have stable and reversible color change under the action of an external electric field. Therefore, the light transmittance of the EC materials may be controlled by control of the electric field.
Polymer dispersed liquid crystal (PDLC) is a material in which a liquid crystal is dispersed in an organic solid polymeric matrix in the form of droplets in micrometers. As an optical axis of a droplet formed by liquid crystal molecules is freely aligned, the refractive index of the droplet is unmatched with the refractive index of the organic solid polymeric matrix, so light is intensely scattered by the droplet when running through the organic solid polymeric matrix, and hence the opaque state is achieved. The application of the electric field may adjust the alignment of the optical axis of the liquid crystal droplet. When the refractive index of both is matched, the transparent state is achieved.